Ab initio investigation of the intermetallics in the Nb–Sn binary system

Abstract The elastic and thermodynamic properties of the stable intermetallics in the Nb–Sn system were studied by the first-principles pseudo-potential plane-wave method based on density functional theory. The elastic constants, Debye temperatures, bulk, shear and Young’s moduli and Poisson’s ratios were calculated for all the phases. Nb 3 Sn has the highest bulk, shear and elastic moduli of the Nb–Sn intermetallics. The elastic properties at 0 K and the Debye temperatures of the Nb 6 Sn 5 and NbSn 2 phases are reported for the first time. The enthalpies of formation were calculated for all the intermetallics. The finite-temperature elastic properties of the Nb and Nb 3 Sn were calculated using the quasi-static approximation. The thermal expansion coefficients of Nb and Nb 3 Sn were also obtained.